Computer users rely upon computers for information related to any number of topics. The information is typically furnished in the form of an electronic document that is accessible by a computer. For example, a “help” manual is a document that describes various topics of an application program. Help manuals are commonly distributed on compact disc or online, such that the user can access help manuals via the computer. Help manuals and other electronic documents are typically organized into units of topic content and a table of contents that enables the user to jump to the desired topic content.
Typically electronic documents are updated over time as new information needs to be added or topic contents change. Document updates are quite common with respect to help manuals because the application programs to which they relate are frequently updated with new features or different functionality. When a user receives the updated help manual, the user typically does not want to reread material that is unchanged from the previous version of the help manual. Rather, the user typically wants to read only the new or changed portions of the updated help manual.
Unfortunately, in order for the user to identify new topics and changes to topic contents, the user must visually compare the updated help manual to the previous help manual. This can be extremely time-consuming, particularly when the help manual is large. For example, a help manual for a large application program can include thousands or tens of thousands of topics. In addition, such manual comparison of help manuals can be a tremendous waste of time because often the majority of content in a later version does not change. As a result, the user must wade through large amounts of content in the later version that he/she has already read in the earlier version to find new or changed content.
Therefore, there is a need for a mechanism to indicate to the user relevant changes in structured documents so that the user does not need to manually determine such changes.